Banca de DEFESA: DANILO OLIVEIRA DA COSTA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : DANILO OLIVEIRA DA COSTA
DATA : 03/11/2020
HORA: 09:30
LOCAL: Santo André
TÍTULO:
METHANE EMISSIONS IN A HIGHLY URBANIZED TROPICAL RESERVOIR AND THE INFLUENCES OF WATER AND SEDIMENT CHARACTERISTICS
PÁGINAS: 40
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Ambiental
RESUMO:
The influence of use and occupation around reservoirs land in highly urbanized areas provide a great contribution of organic matter loads, which in addition to affect water quality, alter ecosystem services and influence CH4 emissions. The combination of high temperatures and eutrophic conditions in a tropical urban reservoir can potentially increase methane flux in water-atmosphere interface. In an order to investigate the interference of pollution and seasonality on methane fluxes in a highly urbanized tropical reservoir in São Paulo- Brazil, four sampling stations in different degrees of pollution were established from May 2018 to March 2019 considering spatial-temporal dimensions and water and sediment characteristics. Water and sediment variables analyses were carried out followed by statistical analyses and random Forest (RF) model to understand the interactions between water and sediment characteristics and CH4 flux besides rank the most important predictors for methane flux. The analysis of variance showed significant differences on methane flux in relation to seasonality (Kruskal-Wallis, p = 0.00026), except between fall and winter (p = 0.05110). The highest flux was observed during the summer (G3=722.0 mg CH4 m-2 d-1 and G2=439.2 mg CH4 m-2 d-1).Our results for carbon, phosphorus and nitrogen both in the water and sediment in all sampling stations showed clear anthropogenic impact. The RF model pointed to seasonality, temperature and pH as the main predictors on CH4 flux in Guarapiranga reservoir, demonstrating an exponential increase in methane flux in warm waters (above 29ºC) during the summer and pH close to 7.0. This is the first study to quantify CH4 flux in reservoir located in the most populous southern hemisphere region. Ours results provides an advance in the understanding about factors which governs CH4 flux in tropical urban reservoirs and at the same time make an alert for government leaders showing that pollution in the reservoir can potentially increase CH4 and consequently contribute to effects of global warming.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1646410 - ROSELI FREDERIGI BENASSI
Membro Titular - Examinador(a) Externo à Instituição - PLINIO CARLOS ALVALÁ - INPE
Membro Titular - Examinador(a) Externo à Instituição - CRISTINA ROSSI NAKAYAMA - UNIFESP
Membro Suplente - Examinador(a) Interno ao Programa - 1814655 - LUCIA HELENA GOMES COELHO
Membro Suplente - Examinador(a) Externo à Instituição - MARCELO LUIZ MARTINS POMPÊO - USP